1. Field of the Invention
This invention concerns a process for the hydrogenative conversion of heavy oils and residual oils, used oils and waste oils, mixed with sewage sludge.
More particularly, the invention relates to a process for the hydrogenative conversion of heavy oils and residual oils, used oils and waste oils, mixed with sewage sludge in a typical liquid phase hydrogenator with gases containing hydrogen, with the addition of a finely ground substance that preferably has a large internal surface area, as additive.
2. Discussion of the Background
The disposal of industrial and municipal sewage sludge presents a serious problem and at the same time a challenge to society. Industrial and municipal sewage sludges frequently contain constituents which create environmental problems and thereby preclude the direct application of the sludge to agricultural land, its disposal in landfills, by combustion or by pyrolysis processes (Kranich et al, Hydroliquefaction of Sewage Sludge, National Conference or Municipal and Industrial Sludge Utilization and Disposal, 1980, pp. 137-140).
One method of treating organic waste products is to hydrogenate the waste products in the presence of raw oils such as heavy oil, residual oil, used oil and waste oil, for example, as taught in U.S. application Ser. No. 07/172,225. In these processes, the raw oil and waste products are mixed with hydrogen gas and heated in one or more hydrogenation reactors. The hydrogenation may be accomplished in either the liquid or solid phase and may be facilitated by the incorporation of various additives into the hydrogenation mixture.
Depending on the desired extent of conversion and tendency toward coke formation of the raw material, a disposable additive, activated coke from anthracite or lignite, carbon black, red mud, ferric oxide, furnace dust, and the like, may be used as an additive. Hydrogenation of the raw oil in the presence of organic waste products converts quantities of the waste products into commercially important gaseous reaction products as well as valuable liquid hydrocarbon products.
A need continues to exist for improved processes for the hydrogenation of raw oils and waste products, particularly sewage sludge.